Voriconazole

Restricted
Restricted

C. diff Risk

Low

Oral Bioavailability

Excellent

Approximate Cost

Spectrum Of Activity

Dosing

Severe impairment (Child-Pugh C)
Should only be used if benefit outweighs risk

Mild to moderate (Child-Pugh A/B)
Standard loading dose then reduce maintenance by 50%

Requires Infectious Disease consultation for use OR completion of the Restricted Antimicrobial order form for approved indications

IV: 6 mg/kg IV every 12 hr x 2 doses then 4 mg/kg IV every 12 hr

PO: 400 mg PO evey 12 hr x 2 doses then 200 mg PO every 12 hr

Dose reduction may be required if low body weight (< 40 kg)

General Information

Acceptable Uses

Broad-spectrum antifungal therapy needed and one of the follwoing criteria met:

  • SCr >2.5 or doubled from baseline

  • Patient receiving tacrolimus, cyclosporine, aminoglycoside, or cyclophosphamide

  • BMT or solid organ transplant patient

Unacceptable Uses

  • Candidiasis/Neutropenic fever: Voriconazole should not be used as first-line therapy for the treatment of candidiasis or for emperic therapy in patients with neutropenic fever

Common Usage

Candida infections both mucocutaneous and invasive - i.e. Candidemia.

Antifungal prophylaxis in immunocompromised patients.

Drug Monitoring

Lab

  • Therapeutic drug monitoring may be helpful to ensure adequate concentrations and exclude toxicity (Discuss with ID).

  • Baseline LFTs and weekly for the first month

  • Serum trough levels at steady state (5-7 days). Target 2-5 mcg/ml

Clinical

  • QTc interval in patients at elevated risk

  • Hypersensitivity

  • GI effects

  • visual disturbances

Adverse Effects

  • Drug interactions

  • QTc prolongation

  • Hepatic enzyme abnormalities

  • Rash - up to 20%

  • Visual disturbance

  • Fluorosis

  • ¬†GI upset

Major Interactions

CYP450 interactions ++.

Other QTc prolonging agents.

Recommend review of pt medications due to high frequency of significant interactions.

Pharmacology

Antimicrobial class: Triazole antifungal, Second generation

Pregnancy category: D

CSF penetration: Therapeutic

Lung penetration: Therapeutic

Urine penetration: Poor